you are doing the right thing by starting early. the magic of compound interest is amazing, but it needs time to work. if i had started when i was 20, my retirement account would be alot higher than what it is now because of the extra 7 years of compounding interest.
with 10% interest, an amount will double in about 7 years on interest only.
lets say you are 20, you start with $3,000, you add $100 every month, and you invest in something that makes 10% interest every year. when you are 65 years old, you will have put only $58,200 into it, but the value will have grown to $1,285,708. if it makes 12% a year instead, it would be $2,596,858. the longer it sits, the faster it grows. amazing.
if you start at 30, it would be only $828,525 when you are 65. that is a difference of $1,768,333, just for waiting 10 years. ouch.
the more you can get into it, epsecially early, the bigger the payoff will be in the end.
get a roth ira, that way you will make out better on taxes when you cash in (unless the rules change).
have as much as possible automatically deducted from your paycheck, that way you never see the money and you don't have to remember to do it every couple of weeks.
be agressive, but buy mutual funds instead of individual stocks, and don't put all your money into one thing. individual stocks are much more risky than mutual funds.